1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
RUDIKE [14]
3 years ago
7

1.) Rn-222 decays from 400 grams to 6.25 grams in 240 minutes. How long is one “half-life.

Physics
1 answer:
KiRa [710]3 years ago
7 0

Answer:

40

Explanation:

You might be interested in
Kenya has a pile of salt on the counter. She uses a pinch of it for a meal. Which of the following physical properties of the sa
SashulF [63]
C. I learned about this last year
4 0
3 years ago
Read 2 more answers
To solve a problem using the equation for keplerâs third law, enrico must convert the average distance of mars from the sun from
Natali5045456 [20]
1 astronomical unit = 149597870700m
Enrico should divide distance in meters with this number.
3 0
3 years ago
Read 2 more answers
What are the two most important traits between a whale and a shark?
nordsb [41]

Answer:

Both are aquatic animals and are hunters

Explanation:

8 0
2 years ago
Bill is farsighted and has a near point located 121 cm from his eyes. Anne is also farsighted, but her near point is 74.0 cm fro
Arada [10]

Answer:

Explanation:

The lens equation is

1 / f = 1 / di + 1 / do

Where

f is focal length

di is the image distance

do is the object distance

Both Annie and Billy use a glass whose near point is 25cm

Then, the object distance is

do = 25 - 2 = 23cm

The have the same object distance.

Let find the vocal length of bills eye

Given that,

Bill near point is 121cm and distance of the glass from the eye is 2cm

Then,

Image distance of bill is

di_B = -(121-2) = -119cm

object distance do = 23cm

Then,

1 / f_B = 1 / di_B + 1 / do

1 / f_B = -1 / 119 + 1 / 23

1 / f_B = -119^-1 + 23^-1

1 / f_B = 0.0351

Then, f_B = 28.51 cm

Also, let find Annie focal length

Given that,

Annie near point is 74 cm and distance of the glass from the eye is 2cm

Then,

Image distance of Annie is

di_A = -(74-2) = -72cm

object distance do = 23cm

Then,

1 / f_A = 1 / di_A + 1 / do

1 / f_A = -1 / 72 + 1 / 23

1 / f_A = -72^-1 + 23^-1

1 / f_A = 0.02959

Then, f_A = 33.8 cm

Distance of object from the lens when Annie uses Billy glass

Then,

1 / f_B = 1 / di_A + 1 / do

1 / 28.51 = -1 / 72 + 1 / do

28.51^-1 = -72^-1 + do^-1

do^-1 = 28.51^-1 + 72^-1

do^-1 = 0.048964

do = 20.42 cm

Then, the object location from the eye will be, the eye is 2cm from the glass. Then,

do_A = 20.42 + 2 = 22.42cm

do_A = 22.42 cm

Distance of object from the lens when Billy uses Annie glass

Then,

1 / f_A = 1 / di_B + 1 / do

1 / 33.8 = -1 / 119 + 1 / do

33.8^-1 = -119^-1 + do^-1

do^-1 = 33.8^-1 + 119^-1

do^-1 = 0.03799

do = 26.32 cm

Then, the object location from the eye will be, the eye is 2cm from the glass. Then,

do_B = 26.32 + 2 = 28.32 cm

do_B = 28.32 cm

7 0
3 years ago
Liquid water heats up and cools down slowly. What causes this property?
Alja [10]

Answer:

water forms hydrogen bonds

Explanation:

3 0
3 years ago
Other questions:
  • A 0.12 kg block on a horizontal frictionless surface is attached to a spring whose force constant is 330 N/m. The block is pulle
    7·1 answer
  • I Need help please with this question..
    15·1 answer
  • A 500 kg satellite is placed in a circular orbit 6394 km above the surface of the earth. At this elevation, the acceleration of
    5·1 answer
  • In an experiment, a ringing bell is placed in a vacuum jar that does not have any air in it. What best describes why the bell is
    15·2 answers
  • What is the magnitude of the force a charge 25uc exerts on a charge 3mc 35 cm away?
    13·1 answer
  • A 100-m-long wire carrying a current of 4.0 A will be accompanied by a magnetic field of what strength at a distance of 0.050 m
    13·1 answer
  • The door is 3.00 m tall and 1.25 m wide, and it weighs 750 N . You can ignore the friction at the hinges. If Exena applies a for
    5·1 answer
  • I’ll give u BRAINLIEST PLEASE!! HURRY
    14·1 answer
  • Please answer this question
    6·1 answer
  • if quasars often resemble little blue stars, what was it about them that so surprised astronomers when they were dis­covered?
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!